The mainboard is the central component of a computer system and connects all installed components.
Differnt kind of connections and ports can be found on the mainboard. Internal components (RAM, graphics card, CPU, ect.) and also external devices like printer, mouse, keyboard are connected through the mainboard.
With the picture below, we will try to describe and explain some general parts of a mainboard
3. , 4., 5., 12. ports for expansion cards (for example graphics card, sound card etc.)
6., 7. SATA-Ports for HDD/SSD or CD/DVD drive.
8., 9., 10., 11. internal ports and header for power supply, USB-devices, ports from case (audio etc.)
13., 16. BIOS and CMOS-Battery
14. fan connectors
15: external ports for TFT, mouse, keyboard etc.